Bacteria perform cooperative behaviors that are exploitable by noncooperative cheats, and cheats frequently arise coexist with cooperators in laboratory microcosms. However, evidence of competitive dynamics between nature remains limited. Using the production pyoverdine, an iron-scavenging molecule, natural soil populations Pseudomonas fluorescens, we found (1) nonproducers present population; (2) they co-occur (<1cm3 ) pyoverdine producers; (3) retain functional receptors; (4) can use on...

Recent theory has overturned the assumption that accelerating returns from individual specialisation are required to favour evolution of division labour. Yanni et al., 2020, showed topologically constrained groups, where cells cooperate with only direct neighbours such as for filaments or branching growths, can evolve a reproductive labour even diminishing specialisation. We develop conceptual framework and specific models investigate factors initial find selection in groups: (1) is not...

Abstract In bacteria and other microorganisms, the cells within a population often show extreme phenotypic variation. Different species use different mechanisms to determine how distinct phenotypes are allocated between individuals, including coordinated, random, genetic determination. However, it is not clear if this diversity in adaptive—arising because favoured environments—or merely result of non-adaptive artifacts evolution. We theoretical models analyse relative advantages two dominant...

Abstract With any theoretical model, the modeler must decide what kinds of detail to include and which simplifying assumptions make. It could be assumed that models more are better, or correct. However, no model is a perfect description reality relative advantage different levels depends on model's empirical purpose. We consider specific case how relatedness modeled in field social evolution. Different types either leave as an independent parameter (open models), for demography life cycle...

Division of labor occurs when cooperating individuals specialize to perform different tasks. In bacteria and other microorganisms, some species divide by random specialization, where an individual's role is determined fluctuations in biochemical reactions within the cell. Other coordinating across determine which cells will task, using mechanisms such as between-cell signaling. However, previous theory, examining evolution between reproductives sterile helpers, has only considered clonal...

Abstract Most organisms are built from a single genome. In striking contrast, arbuscular mycorrhizal fungi appear to maintain genomic variation within an individual fungal network. Arbuscular dwell in the soil, form mutualistic networks with plants, and bear multiple, potentially genetically diverse nuclei We explore, theoretical perspective, why such genetic diversity might be maintained individuals. consider selection acting between networks. show that could provide benefit at level of...

A Hamiltonian formulation of the guiding center drift orbits is extended to pressure anisotropy and field perturbations in axisymmetric systems. The Boozer magnetic coordinates are shown retain canonical properties anisotropic plasmas with finite electrostatic electromagnetic perturbed fields that solely affect parallel component vector potential. equations motion developed coordinate frame satisfied by direct verification velocities. numerical application illustrates significance retaining...

Using a generalized anisotropic tokamak equilibrium and an exact guiding centre drift formulation, the effect of parallel perpendicular anisotropy on toroidal precession is investigated. Significant differences between pressure are observed. While Shafranov shift not sensitive to ratio pressures p⊥/p∥, deepening magnetic well found be p⊥/p∥. Here, diamagnetic identified by Connor et al 1983 Nucl. Fusion 23 1702 depend crucially deposition energetic ions which depends, leads test particle...

Ideal MHD yields at best inconclusive predictions about the stability of LHD heliotron for ⟨β⟩ ⩾ 3%. We investigate impact drift stabilization ballooning modes inward-shifted configuration (vacuum magnetic axis R 0 ∼ 3.5 m). The background equilibrium is considered anisotropic in which neutral beam ions contribute 1/4 fraction total diamagnetic beta, ⟨β dia ⟩. A corrected mode equation obtained from linearized gyrokinetic expanded assuming that hot particle drifts are much larger than...

A drift-magnetohydrodynamic theory is applied to a background anisotropic pressure equilibrium state generate drift corrected ballooning mode equation. The ratio of the frequency hot particle constitutes critical expansion parameter. fast particles thus contribute weakly instability driving mechanism and also diamagnetic stabilisation. This equation used model inward-shifted Large Helical Device (LHD) configuration. In single-fluid limit, unstable band that encompasses third plasma volume...

Electrophoretic‐based (EP) technology is a leading option for black &amp; white reflective display media, notably e‐Readers. There great future potential to extend electrophoretic and other colloidal dispersion based displays into range of new application fields, such as digital signage, wearable “smart windows”. These applications require novel particle fluid concepts, which present many materials design challenges; especially bright colour, image stability ultra low power consumption. The...

ABSTRACT In bacteria and other microorganisms, the cells within a population often show extreme phenotypic variation. Different species use different mechanisms to determine how distinct phenotypes are allocated between individuals, including coordinated, random, genetic determination. However, it is not clear if this diversity in adaptive—arising because favoured environments—or merely result of non-adaptive artifacts evolution. We theoretical models analyse relative advantages two dominant...

A Hamiltonian/Lagrangian theory to describe guiding center orbit drift motion that is canonical in Boozer magnetic coordinates developed include full electrostatic and electromagnetic perturbed fields axisymmetric tokamak geometry. Furthermore, the radial component of equilibrium field covariant representation retained background state extends anisotropic plasma pressure conditions. gauge transformation on vector potential imposed guarantee structure frame. Perturbed nonlinear wave-wave...

The authors model only one pole pitch of a shaded-pole motor, exploiting the inherent periodicity boundary conditions. Excitation for is derived directly from applied stator voltage which not restricted to any particular time variation. Rotor motion simulated by moving rotor in discrete spatial steps and tying this movement step used discretisation excitation waveform. At each position field solution coupled external electrical circuit current determined taking magnetic nonlinearity...